broadcom-diag: Detection of WNDR3400v1

nvram variable "boardtype" is unique for now.
-button gpio were taken from nvram.
-led information was taken from dd-wrt
( http://svn.dd-wrt.com/browser/src/router/libutils/utils.c

 )

I hope that I changed the values correctly.

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 35765